1. Field of the Invention
The present invention relates to a heat exchanger mounted on an air conditioning device and the like.
2. Description of the Related Art
FIG. 9 shows an example of a two-block heat exchanger used as an evaporator in an automobile air conditioning system and the like. The heat exchanger shown in the figure is referred to as a drawn cup type, and is formed by plate-shaped refrigerant distribution parts 3 comprising overlapping rectangular plates 1 and 2 that have had a drawing process carried out thereon and cooling fins 4 bent into an wave shape being alternately layered.
In the refrigerant distribution parts 3, the periphery and center of the plates 1 and 2 are brazed, and thereby a U-shaped refrigerant path R is formed that goes from the refrigerant entrance 5 provided at the top, descending to and returning from the bottom for discharge into the refrigerant exit 6 provided at the top and arranged next to the refrigerant entrance.
In this heat exchanger, the refrigerant is distributed among each of the refrigerant distribution parts 3 in the refrigerant entrance 5, is evaporated in the process of flowing through in the refrigerant paths R, merges together again in the refrigerant exit 6, and flows out of the heat exchanger.
However, problems such as the following can be pointed out concerning the heat exchanger having the structure described above.
Specifically, as shown in FIG. 10, a continuous space T (below referred to as a tank) is formed by the layering of refrigerant entrances 5, and the refrigerant flowing into the heat exchanger is distributed to each of the refrigerant distribution parts 3 in the process of progressing through this continuous space in the direction of the arrows in the figure. However, in the conventional heat exchanger, the refrigerant supplied to the tank T passes with difficulty to the back of the tank T and there is a tendency for much of the refrigerant to flow through the upstream side of the refrigerant paths R. Thus, the flow of the refrigerant stagnates in the downstream side of the tank T. Due to this, the distribution of refrigerant to each of the refrigerant distribution parts 3 cannot be carried out uniformly, and at the refrigerant path R of the tank T positioned downstream, the refrigerant becomes hot, and the heat exchange cannot be sufficiently carried out.
In consideration of the problem described above, it is an object of the present invention to provide a heat exchanger that can realize an improvement in the heat exchange capacity by evenly distributing the refrigerant in the refrigerant paths.